Code:

void getEdgeFaceClippedContactData(AMG3DPlane clippingPlanes[4], const AMG3DVector4 vSubjectVertices[2], const AMG3DContactID subjectIDs[2],    AMG3DContactData *pContactData){AMG3DContactData clippedContactsInputList;AMG3DContactData clippedContactsOutputList;int iCountInputList=0;int iCountOutputList=0;for(int i=0; i<2; ++i) {clippedContactsOutputList.contacts[i].vContactPoint = vSubjectVertices[i];// The clipping edgeclippedContactsOutputList.contacts[i].contactID.ec.iEdge1BoxID= subjectIDs[i].ec.iEdge1BoxID;clippedContactsOutputList.contacts[i].contactID.ec.iEdge1Index= subjectIDs[i].ec.iEdge1Index;// The subject edgeclippedContactsOutputList.contacts[i].contactID.ec.iEdge2BoxID= subjectIDs[i].ec.iEdge2BoxID;clippedContactsOutputList.contacts[i].contactID.ec.iEdge2Index= subjectIDs[i].ec.iEdge2Index;// The third edge that makes up the subject vertexclippedContactsOutputList.contacts[i].contactID.ec.iEdge3BoxID= subjectIDs[i].ec.iEdge3BoxID;clippedContactsOutputList.contacts[i].contactID.ec.iEdge3Index= subjectIDs[i].ec.iEdge3Index;}iCountOutputList = 2;// For each clipping planefor(int i=0; i<4; ++i) {clippedContactsInputList = clippedContactsOutputList;iCountInputList = iCountOutputList;iCountOutputList = 0;AMG3DVector4 vS = clippedContactsInputList.contacts[iCountInputList-1].vContactPoint;int ivSIndex = iCountInputList-1;// Clip each subject vertex against clipping plane and store three edges for each contact to form contact IDfor(int j=0; j<iCountInputList; ++j) {// Vertex J is inside the clipping planeAMG3DScalar fD; // Determines the penetration depth of each contact, not required here (face plane only)if(pointInsidePlane(clippedContactsInputList.contacts[j].vContactPoint, clippingPlanes[i], &fD)) {// Vertex S is outside the clipping plane, clip with respect to Sif(!pointInsidePlane(vS, clippingPlanes[i], &fD)) {AMG3DLineSegment lineSegment(clippedContactsInputList.contacts[j].vContactPoint, vS);AMG3DScalar fT;AMG3DVector4 vIntersectionPoint;bool bIntersect = clippingPlanes[i].intersects(lineSegment, &fT, &vIntersectionPoint);clippedContactsOutputList.contacts[iCountOutputList].vContactPoint = vIntersectionPoint;AMG3DContactID contactvS = clippedContactsInputList.contacts[ivSIndex].contactID;if(contactvS.ec.iEdge1BoxID==1) { // Point has been previously clippedcontactvS.ec.iEdge2BoxID = 1;contactvS.ec.iEdge2Index = i; // Now, this vertex ID consists of 2 clipping planes}else {contactvS.ec.iEdge1Index = i;}clippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge1BoxID= 1;clippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge1Index= contactvS.ec.iEdge1Index;clippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge2BoxID= contactvS.ec.iEdge2BoxID;clippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge2Index= contactvS.ec.iEdge2Index;clippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge3BoxID= contactvS.ec.iEdge3BoxID;clippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge3Index= contactvS.ec.iEdge3Index;iCountOutputList++;break; // Once vertex clipped against this plane, continue to the next plane}clippedContactsOutputList.contacts[iCountOutputList].vContactPoint = clippedContactsInputList.contacts[j].vContactPoint;AMG3DContactID contactIDs = clippedContactsInputList.contacts[j].contactID;// No change, store current subject edge IDsclippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge1BoxID= contactIDs.ec.iEdge1BoxID;clippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge1Index= contactIDs.ec.iEdge1Index;clippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge2BoxID= contactIDs.ec.iEdge2BoxID;clippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge2Index= contactIDs.ec.iEdge2Index;clippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge3BoxID= contactIDs.ec.iEdge3BoxID;clippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge3Index= contactIDs.ec.iEdge3Index;iCountOutputList++;}else if(pointInsidePlane(vS, clippingPlanes[i], &fD)) { // Vertex J is outside the clipping plane, clip with respect to JAMG3DLineSegment lineSegment(clippedContactsInputList.contacts[j].vContactPoint, vS);AMG3DScalar fT;AMG3DVector4 vIntersectionPoint;bool bIntersect = clippingPlanes[i].intersects(lineSegment, &fT, &vIntersectionPoint);clippedContactsOutputList.contacts[iCountOutputList].vContactPoint = vIntersectionPoint;AMG3DContactID contactvS = clippedContactsInputList.contacts[ivSIndex].contactID;AMG3DContactID contactJ = clippedContactsInputList.contacts[j].contactID;if(contactJ.ec.iEdge1BoxID==1) { // Point has been previously clippedcontactvS.ec.iEdge2BoxID = 1;contactvS.ec.iEdge2Index = i;}else {contactvS.ec.iEdge1Index = i;}// Clipping, take 1 clipping edge and 1 subject edgeclippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge1BoxID= 1;clippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge1Index= contactvS.ec.iEdge1Index;clippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge2BoxID= contactvS.ec.iEdge2BoxID;clippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge2Index= contactvS.ec.iEdge2Index;clippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge3BoxID= contactvS.ec.iEdge3BoxID;clippedContactsOutputList.contacts[iCountOutputList].contactID.ec.iEdge3Index= contactvS.ec.iEdge3Index;iCountOutputList++;break; // Once edge clipped against this plane, continue to the next plane}vS = clippedContactsInputList.contacts[j].vContactPoint;ivSIndex = j;}}(*pContactData) = clippedContactsOutputList;(*pContactData).iNumContacts = iCountOutputList;}